QA‎ > ‎August 18, 2009‎ > ‎

Posterior acoustic enhancement

Note on this view of the bladder, the very bright white artifact distal to the bladder. This is posterior acoustic enhancement; in this case it is caused by sound traveling at higher speeds through the bladder because it is fluid-filled. It then hits the wall of the bladder, where there is less attenuation of the signal and an increase in echogenicity occurs. It is important in these cases to decrease the gain in that portion of your image, as it can mask any abnormality (i.e., free-fluid) that you would be looking for. To do this on the Phillips, adjust the TGC (time-gain compensation), which are the sliding equalizer-type buttons on the upper-right side of the control panel. In other machines, such as Sonosites, you can adjust the "Far Gain" knob to achieve this.